Collapsible structure



Jan. 6, 1942. H. A. FARRAND 2,269,363

GOLLAPSIBLE STRUCTURE Filed March 16, 1939 11 Sheets-Sheet l Jan; 6, 1942. H. A. FARRAND 2,269,363

COLLAPSIBLE STRUCTURE Filed March 16, 1939 ll Sheets-Sheet 2 4.

Jan. 6, 1942. H. A; FARRAND 2,269,363

COLLAPSIBLE STRUCTURE Filed March 16, 1939 11 Sheets-Sheet 5 JZZZZZZ Jan. 6, 1942. H. A. FARRAND COLLAPSIBLE STRUCTURE Filed March 16, 1939 ll Sheets-Sheet 4 Jan. 6, 1942. H. A. FARRAND v 2,269,363

COLLAPS IBLE S TRUCTURE Filed March 1 ll Sheets-Sheet 5 Jan. 6, 1942. H, A. FARRAND 2,269,363

GOLLAPSIBLE STRUCTURE Filed March 16, 1939 ll Sheets-Sheet-G Jan. 6, 1942. H. A FARR-AND 2,269,363

COLLAPS IBLE STRUCTURE Filed March 16, 1939 11 Sheets-Sheet 7 Jan. 6, 1942.

H. A. FARRAND COLLAPSIBLE STRUCTURE Filed March 16, 1939 11 Sheets-Sheet 8 Jan. 6, 1942. H. A. FARRAND COLLAPSIBLE STRUCTURE Filed March 16, 1939 ll ShetsSheet 9 Patented Jan. 6, 1942 UNITED. ESTATE-S PATENT OFFICE onmrsmtasraucwm Hiram A. Farrand, Berlin, N. H. Application March 16, 1939, Serial-No. 262,324

'34Claims; (o1.'- 1-s9-'-s1 This invention relates to collapsible -.devices, i. e. devices which are convertible fromlone form to another in such manner as :to :be reduced to and confined in compact shape, for :storagenor transportation purposes, ylet capable of projection outwardly, in whole :or in part, from such compact shape into a substantially straight and rigid formation, which may attain .-a comparatively extended :longitudinal dimension, to function as a column, beam, -strut,.canti lever or other structural support, and which as :such .may be applicable to a Wide variety of uses. Furthermore, the present invention relatessto that class of adjustable devices which .are compounded from normally separable, non-rigid members, which, byreason of suitable connective means, may be united to form a comparatively long, rigid, structure, which latter may be dismembered to free the assembled component members in such manner as .to permit of their-being disposed of in a relatively restricted state.

Devices of this character have-been known to the prior art, wherein the component members consisted of flexible strips of resilient material interlocked at their edges, or otherwise engaged by laterally extending elemenlts placed at intervals along the longitudinal extension of the structure. It 'has" been the practice in some prior art devices to disposeof such portions'zof' the component members as are not being-used and, I

when such unused portions are lnthe released or disconnected state, by winding all such parts together, simultaneously, into a common coil. Even in the very simplest of such arrangements difficulties are encountered in operation, since j,

of are assembled, and tor removing the choircling bands during disassembling of the component :membe The encircling bands of the prior artdevices, beingseparate and not connected in any way one withanother engage the structure frictionally and are subject to relative displacement along the structure, requiring, in instances where a rigid relationship between the bands and the composite structure is essential, the manual placing and removal of locking pins in and out of aligned openings in the bands and the encircled structure.

the circumferential distance around the coil can;

never be the same for any *two convolutions, Consequently, the rate-of take-up or delivery of the different strips proceeds at unequal rates at the reel, or coil, wh'ile the -'rate of movement of thesesame strips-while connected togetherinthe compound structure is the same'for all. Obvi ously, a surplus or deficiency will accumulate *in one or more of the components/between the coil and the point of assembly.

In other prior art'devices employing the edge interlocking type of component members 'separate places of storage are provided "for each member; and, in addition tothe means' by' which the locking and unlocking of the edges of "the components are accomplished, the devices are provided with special means for placing discrete bands around the:assembled component members at relatively spaced points along the lengthj of the structure as the component members --th ere- One of the .ob-jectsof thepresent-invention in accommodations for-the separated-portion of the components, including independent storageand regulating facilities for each member, and the provision of-means for embracing the assembled ecmponents of the extended portion of the structure,-is :toaprovide means for inter-connecting theernbracing elements. The facilities thus employed rare made ,to react in responseto demand, by taking up or delivering equivalent portions'of all components including the chain of interconnected bracing elements during any change being made in the length {of the compound structure. This procedure has, particular advantages where two or "more groups of component'members have widely differing physical characteristics.

The employment of "the later-ally extending interlocking elementsinthe form'of teeth and holes, 'hooks or other-"undesirable projections constituting permanently aihxed engaging means located along the length of the flexible strip members as have been used in :the prior art structuresabove noted, have been eliminated by the present invention. According 'to the present invention .a smooth uninterrupted surface and edge is preserved throughout-the efiective length of all strip members andwholly independent and separable means is. relied .upon to bind the difierentcomponents into-a structural whole.

By reason 'of this provision thebinding elements, when notserving as partof the united structure, may slip along over the smooth surfacesof the strips without hindrance: inthe process of ,moving toand from storage. In the absence of-permanentlya-flixed connective elements a system is introduced whereby all components, though separable and-free when disconnected, automatically resume their respectiyepositions and duties when drawn back into renewedassociation at thepoint of assembly with the other components of the united structure.

Furthermore, by this method of segregating the various components according to characteristics and duties of each, the resultant structure may be made to assume the form of a reinforced beam or column, wherein the continuous strip members enact the role of a longitudinal web and the binding elements constitute a system of lateral bracing,the latter being distributed, automatically, over the length of the web and at definite and correct intervals thereon at the time of their assembly. It is also possible by this method to generate fractional parts of the total available length of unit structure, and in such manner that each fractional part retains its integrity regardless of changes occurring elsewhere. That is, the length of the unitary structure may be altered at any other locality by adding or subtracting other portions without disturbing the stability of the part under consideration.

It is to be observed that in the devices of the present invention the component members, alone, though entirely independent when separated, react cooperatively during the time of assembly to present themselves in proper order and equivalent proportion to create the desired length of unit body, and that no feeding mechanism, extraneous thereto, is required. Furthermore, no readjustment of relations is called for subsequent to their entry into union. I

Other objects of my invention will be in part obvious, and in part pointed out more in detail hereinafter, reference being had to the accompanying drawings, of which:

Fig. 1 is a perspective view of a portion of one form of composite structure made and assembled in accordance with the present invention;

Fig. 2 is a side elevation, partly in section, of a device for assembling and disassembling the component parts of'the structure shown in Fig. 1, showing said structure partially extended;

Fig. 3 is a plan view of the structureshown in Fig. 2; V V

Fig. 4 is a transverse sectional elevation taken on the line 4-4, Fig. 2;

Fig. 5 is a transverse sectional elevation taken on the line 5-5, Fig. 2;

Fig. 6 is a side elevation of a second form of composite structure made and assembled in accordance with the present invention;

Fig. '7 is a fragmentary perspective view illustrating a portion of the structure shown in Fig. 6;

Figs. 8 and 8a constitute a side elevation of a device for assembling and disassembling the structure of Fig. 6 and showing said structure partially extended; 7

Figs. 9 and 9a constitute a transverse sectional elevation taken on the line 99, Fig. 8;

Fig. 10 is a sectional plan view taken on the line Ill-l0, Fig. 8;

Fig. 11 is a front view of a detail of the mechanism shown in Fig. 9;

Fig. 12 is a sectional elevation taken on the line l2--l2, Fig. 11;

Fig. 13 is a perspective view of a third form of structure made and assembled in accordance with the present invention;

Fig. 14 is a side elevation partly in section of an assembling and disassembling device for the structure of Fig. 13;

Figs. 15 and 15a constitutea transverse elevation of the collapsing device and composite structure shown in Fig. 14;

Fig. 16 is a sectional plan taken on the line Iii-I6, Fig. 15;

Fig. 17 is a fragmentary perspective view of a fourth form of composite structure made and assembled in accordance with the principles of the present invention;

Figs. 18 and 18a constitute a side elevation, partly in section, of a device for assembling and disassembling the component parts of the composite structure shown in Fig. 17;

Fig. 19 is a sectional plan View taken on the line l9l9, Fig. 18;

Fig. 20 is a perspective view of one of the component parts of the structure of Fig. 1'7;

Fig. 21 is a sectional plan view taken on the line 2I-2l, Fi 18.

The devices shown in Figs. 1, 2, 3, 4, 6, '7, 8, 8a, 9,9a, 10, 13, 14, 15, 15a, 16, 17, 18, 18a, 19 and 21 are composite structures formed by the union of two or more members, or elements. These elements taken by themselves are unable to withstand the amount of strain for which the entire composite structure is calculated; norwill their separate and individual resistances together add up to the total strength of the composite structure which they combine to form. Furthermore, when separated from one another each member may be withdrawn from the assembly which constitutes the composite structure in such a way that it may be converted into a form different from that which'it assumed in the assemblage, with its longitudinal dimension materially reduced in such manner as to occupy very much less space than in extension and thus lend itself to compact formation when out of use and thus permit of its being converted into convenient shape for transportation and storage.

The cooperative effect, therefore, is to produce a relatively strong and rigid structure-inherently resistant to tensile, compressive, and torsional stresses about the longitudinal axis of the structure when the elements are in combination with each other and the extraneous elements which maintain the combination, and to lend to portability when displaced therefrom.

In the structure in Figs. 1 to'5 inclusive, two of the component members 'I, l are normally rectilinear flexible strips of spring material, and as such are capable of being bent out of line with reference to their normal longitudinal shape. The strips I, l, shown in Figs. 1 to 4 inclusive are normally of a straight longitudinal extension and of a bent, or nonplanar, transverse shape; sometimes referred to as concavoconvex. Each is in the form of a shallow trough. Being composed of a relatively thin section of spring material the elasticity or flexibility thereof permits them to be forced'out of their normal longitudinal'and transverse shape by bending or coiling. It is further pointed out that wherever such bend or coil takes place, the relative shapes are reversed, with the longitudinal extension becoming bent and the transverse curvature is converted into a straight form. By passing from their rectilinear state in a direction different therefrom the strips are able to cooperate in altering the original state of extension of the composite body. It is to be noted also that whenever the members or elements I, I are bent out of their original shape the strips have an inherent tendency to return to the original nonplanar state in which they are normally rectilinear in the longitudinal direction.

In Figs. 1, 2, 3, 4 and 5 the remaining member of the composite structure is a system of pivotally.

connected links. 2, 2, each link of which is provided with. an elongated hole- 3 through which the pair of strips I, I,pass-. As will be seen by reference to Figs. 1 and 4, each link is'madej up of a rigid plate and the entire system of links are hinged one to another, at their oppositely disposed adjacent ends asindicated at 5. In

this way the links 2, 2 may be folded or drawnout in accordion fashion. When joined with the strips I, I, to produce the composite structure, the links 2, 2-, take 'a zigzag course along the strips. When withdrawn from their combination they may rest in folded shape within a storagespace as shown at 6 in Fig; 4. While the links 2, 2 are in this latter condition the strips I, I, lie only in loose contact within the openings 3 and are free-to pass the-rethrough in either direction.

It is to be remarked that the strips I, I, in Q Figs. 1, 2, 3 and 4 are located in parallel position with their concave surfaces facing and only touching at their extreme edges, thus forminga rod of substantially elliptical tubular cross section. It may also be noted that this tubular rod is surrounded by the links, 2, 2. ings 3 in the links 2 are such that when the links 2, 2 are stretched in zigzag formation along the tube with the extreme points I, 'I of said openings engaging the edges 8, 8 of the tube, the interior edge contour of the opening snugly fits the external cross sectional contour of the tube where it comes in contact therewith.

Wheneverthe link system is in this stretched The openposition and a strain occurs along the composite and in loose contact. The diagonally extending links 2, 2, are seen folded and. at rest in their storage space, while thestrips I, I, forming the tubular portion are free to slip easily through the series of openings 3, 3 in the links which lie substantially at right angles to the longitudinal axis of the tube. As a matter of fact, the tubular formation II! moves through the openings and passes on down beyond the base plate II, of the storage chamber 6 to a point x Where the strips I, I, bend laterally into separate opposite trans-' verse paths and follow the peripheries of guide rolls or pulleys I2, I2 guided by freely rotatable guide roller I3, I3 for a distance, and then move upward to points of engagement or attachment I4, I4 on the winding drums of reels I5, I5, where they form into individual coils 'I 6, I6, (see Fig. 2)

Inasmuch as all the essential parts entering into the composition of the structure may be withdrawn therefrom and stored in a comparatively small space, and, because of the fact that varying quantities of such components may thus be withdrawn in proportion, it is possible to reduce, or increase, the length of the structure at will, and to whatever extent the supply of parts provides for.

Figs. 6, 7, 8, 8a,, 9, 9a., and 10 show a slightly different arrangement from that exhibited in Figs. 1,2, 3, 4, and 5. In this'style of structure, While'the strips Ia, Ia, are the same as the strips I, I. in thepreviousc'ase, it will be 'observed that they are. placed back to back, rather than face to face, i. e. with their convex sides facing and touching only along their middle lines. The diagonal bracing links 20, 2a; are formed of lengths of fiat side-bars; linked together somewhat in the form of a sprocket chain. When the chain bars 2a, 2a,,and the strips I a, la, are in structural combination, thestrips pass through rectangular openings 3a, 30 formed by the side bars 2a, 2a, and hinge-pins 5a., 5a 5b, 5b, and thus are. surrounded by the chain or link system which lies in a zigzag coursein contact with the four strip edges 8a,. 8a. The dimensions of the openings 3a are so related to the shape of the strips that thefour edges of the latter contact the chain' at the junctures of the side bars 2a, 2a, with the hinge pins 5a, 5a, 5b,.5b; and when forced to the limit of the extended zigzag course, the chain holds the strips in a tight embrace,

with the longitudinal middle portions of the strips Ia, Ia, pressed tightly one against the other. It will be noted that the hinge pins 50; and 5b form rigid elements whichengage the longitudinal edges of. the strips Ia, Id and that these hinge pins are connected for free pivotal, relative. movement by the links 2a, 2a diagonally crossing from edge toedge of' said strips. In this form of my invention, the element referred to in certain of the appended claims comprises a pair of links 2a, 2a and hinge pins 5a, 5b connecting said pairs of links, these elements being' connected for free, pivotal, relative movement'by alternate pairs of the links 2a, 2a.

When withdrawn from the columnar combination, the chain links 20., 2a, foldaccordion-wise in the same fashion as the links 2, 2, of the styleernployed in Figs. 1 and 2. This folding is illustrated in Figs. 8' and 9, at the lower portion of these figures.

In Figs. 6 7, '8', 8a, 9, 9a and 10 inclusive, an additional system of foldable link-bars 20, 20 is shown. These bars are hinged together by pins 2|, 2| and by alternate hinge'pins 5b, 5bof alternatelink joints of the sprocket-type chain. This additional system of bars, 20, 20 is arranged in the'form of toggle arms and of such length that when extended with all joints, or hinges, 5b; 2!, 5b, 2|, etc. in a straight'alignment, the sprocketlike chain'i's stretched toits full zigzag limit with the hinge-pins 5a, 5a, 5b, 5b, 2|, 2| pressing tightly upon the edges 8a, 8a of the strips la, la lying within its embrace. This is clearly illustrated in the upper portion of the structure shown in Fig; 9-911 and in Fig. '7. When any set of hinge pins as 52), 2|, 5b lie on astraight line the joints of the toggle-bars 2|), 20 are said to be on a dead center; and, by reason of the resilient back pressure caused by the above described embrace, they maybe easily displaced in a lateral direction from that position. To overcome instability arising from this condition, provision has been made, allowing the joints at 2|, 2| to move beyond the dead center position in a manner so as to permit the hinge pins 2|, 2|, to rest against the adjacent 8c edges of the strips Ia, Ia. To allowfor this slight degree off-center position the diameters of the pins 2|, 2| are of less diameter where they contact the strip-edges than the diameters of the hingepins 5b, 573, immediately above and below. Having assumed'this off-center position, the back pressure referred to above operates to keep each edges 8a, 8a ofstrips- I a, Ia.

In view of the common attachment of the toggle links 20, 20 with the sprocket-like chain systemthrough hinge-pins b, 5b, the collapse of the toggle system may proceed in unison with that of the sprocket chain system and open out in unison, therewith. When out of combina tion the toggle system remains stored alongside the sprocket chain system, and the two systems may be fed out link-set by link-set seriatim, that is, in parallel progression. Obviously, the strips move freely through the openings 3a, in the sprocket-like chain of links in storage, quite as in the case of the links shown in Fig. 4. Thus, due to the employment of the system of toggles, a composite columnar structure capable of self maintenance throughout varying degrees of extension is provided, since each set of toggles insures the stability of the composite structure within the influence of its span. Consequently, the length of the columnar structure may be increased or diminished by adding to or taking away the requisite number of unit-sets, thus described without weakening the adiacent structure.

Figs. 8, 8a, 9, 9a are a mechanism which embodies a structure similar to that shown in Figs. 2, 3, 4 and 5, together with a complement of devices to aid in building up and withdrawing from this composite structure, the several component members used therein. In these figures the spring strips Ia, I a, are shown leading down below the space 6a employed for the storage of the links 20., 2a, and into a chamber 22 below the base IIa, where they contact the guide rolls I211,

and, separating at the point :cl, pass in opposite ways following curved paths lying between the peripheries of the rollers I2a, I2a, and the series of antifriction rollers I3a, I3a. After following the distance of approximately one half a circle,

each strip leave the guide rollers and passes up to an attachment on the reel I5a, directly above, where it forms into a coil around the reel-drum similar to the coils I6, I6 of Fig. 2.

The reels I5, I5, I500, I5a, are made to conform to my invention as described in my prior U. S. Patent No. 2,056,844, on Transmission mechanism and in particular that embodiment of the idea as illustrated in Figs. and 16 of that patent. A reel of such nature automatically operates to wind a concavo-convex spring strip into a coil over its drum whenever the strip is pushed forward and into it from a tangential direction. It also allows the strip to unwind automatically from such a coil when not under restraint.

Consequently the reels, I5, I5, I5a, I5a, receive the strips I, I, and la, Ila and convert them into coils for storage when ever they are thrust toward the reels during the process of reduction in the composite column-length, and they likewise, pay out whatever length of strip is needed to build up further, the composite column length, as required. Th reel I5, I5, I5a, I511, are rotatable on arbors 23, 23, which are mounted between two walls 24, 24.

It will be seen that with a supply of component parts in storage, as shown in Figs. 8 and 9, one may call upon any number of complementary pieces and build up whatever length of columnar structure may be desired within the total available. Also that the length of any such composite column may be reduced to whatever extent may be desired by simply thrusting down on the end of the column with sufiicient force to overcome whatever resistance may oppose the action. The several complementary parts making up the deposed portion of the column will pass out of combination and enter their respective storage positions, automatically.

Figs 8, 9 and 10 are side elevation, end elevation and plan, respectively, of a mechanism embodying the composite structure shown in Figs. 6 and 7 together with a complement of means for storing a proper supply of parts composing the columnar structure and for controlling and guiding the several parts during their passage from one position to another in to and out of combination. When the component parts are withdrawn from the combination they move downward in the same fashion as described for the mechanism shown in Figs. 2 and 3, with the diagonal members 2a, 2a, and toggle arms 20, folding compactly, while the strips Ia, Ia pass on through to separate ways and follow circular paths in practically the same manner as previously described.

Up to this point the two styles of structure and mechanism operate in quite similar fashion. But in the matter of control at the point where the several parts enter into the column combination each style employs an individual meansnot common to both.

In Figs. 2, 3 and 4, two walls 25, are mounted on top of and extend transversely to the walls 24, 24 between which the reels or drums I5, I 5 rotate. Projecting inwardly toward the column from each wall 25, is a bar 26, which supports a brake shoe 21. Located at the top and bottom of shoe 21, is a diagonal slot 28, through which projects supporting pin 29, which is mounted in bar 26. Attached to the lower end of each shoe is a tension spring 30, which in turn is hooked to a hook ear 3I, on the bar 26. The tension of these springs is to hold the brake shoes 21 in frictional contact with the sides of the diagonal numbers link elements 2, 2, with the purpose of retarding the opening out of the links, 2, 2, during their movement up into combination and thus insure a close fit of opening 3 of each of the links 2 upon the contour of the tubular strip member III while in combination therewith. A lug 32 is on the outer side of shoe 21, and lying underneath the lug 32, is the end of a lever 33, the opposite end of which extends beyond wall 25. This lever 33 is pivoted to plate 25 at 34, in such fashion that pressure downward on the outer end of the lever will act to raise shoe 26 and release the braking contact from the sides of the links 2, 2. This release is provided for use when in reducing the length of the composite column, freedom must be afforded the links to follow down with the strips into the storage chamber.

As the process of insuring the full opening of the diagonal bars 2a, 2a, of structure illustrated in Figs. 6, 7, 8, 8a, 9, 9a, is dependent upon the functioning of the toggle arms 20, 20, a different system is provided for the guidance and control of the parts where they enter in or withdraw from, the column combination.

In Figs. 8, 9 and 10 the uprights 35, 36, 31 and 31 constitute the walls of the storage magazine 6a provided to hold the diagonal bars 211, 2a and toggle arms 28, 20, when withdrawn from the column combination. These walls arise from, and are mounted upon, the base plate Ila. Also, attached to the base plate Ila are the angle bars 38, 38, upon which are mounted pivots 39, 40, 39 and 40 on which are pivoted guiding arms 4|, 42, M and 42. These guiding arms are provided at their upper portions with arcuate slots 43, 43,44 and 44, the arcs of which ar centered on the pivots 39, 39, 49 and 49 respectively. Mountedron the upperportion of wall 35, and passing through slots 43, 43, are stud :screws 45, 45, whichaot'to guide and retain the guiding arms 4|, 4| in their lateral movements. Mounted at the top of wall 36, and at right angles, (horizontally), thereto is a rigid arm 36a. Upon this arm and passing through slots 44, 44, are stud screws 41, '41, which perform a similar function to studs 45, 45.

In Figs. 6 to 10, inclusive, each set, or pair, of toggle arms 29, 29 is provided with a projecting portion 46 adjacent thehinge 2|. As will be seen by inspection-of Figs. 8,9 and 10 these projecting portions 46 of the toggle arms 29, 2-9, when said arms are rising from storage position, will-come into contact with inclined underedges 41, 41 of the-guiding arms 42, 42, and'be forced toward the edges 80., 8a of the strips la, la positioned at the center of the assembly, as long as the upward movement of the links 29, 29 continues. In Fig. 9 one of the projections 46 is shown closely approaching to a dead center position. On arriving at the extreme left ends 48, 48 of the guides 42, 42, the hinge pins 2 2|, will have passed the dead center position and rest secient to fold of themselves upon further downward movement toward the storage compartment 6a.

Obviously, the composite structures shown in either Figs. 1, 2 and 3, or in Figs. 6,7, 8, 8a, 9

and 9a, may be extended to any length desired,

limited only by the number of link parts and the length of the strips available. Likewise any reduction may be made from any length extended.

Whenever it is found desirable to projectand hold any particular length of extension in a 1- manner to resist any force that may be applied tending to alter that length, as would be the case where the column is called upon to sustain a load at its top, some means to overcome the force of gravity is required in order to prevent the column from collapsing vertically. In Figs. 2, 3, and 4 is shown a clamp devic installed for such purpose. In this device, cam levers 59, 59 are mounted upon square shafts 5|, 5| which in turn are mounted in hearings in plates 52,52, at either end. The plates 52, 52 are, in turn attached to the walls 25, 25. Alongside each cam lever and mounted on the same shaft, is a hook lever 53 attached to tension spring 54. The lower end of sprin 54 is hooked into an ear 55, attached to wall 24. The object of this spring is to maintain a contact of the'cam lever 59, on the edges 8, 8 of the tubular formation of IO composed of the strips 1. -On each end of one of the plates 52, is an angle bar 56, and each such angle bar carries 'a stud screw 51, which acts as a pivot for the U-shaped lever 58. As long as the U-shaped lever 58, remains in the raised position shown by the full lines of "the drawing, Fig. 2, the points of the camv levers 59, 59, will remain in contact with the edges 8, 8 of the tubular formation 19 of strips These cam levers both lie ordinarily at such angles to the edges :of the strips 1, that any reverse movement .of the strips in .a down direction will be checked ;as .by a pawl. When, however, a down movement is desired, as would be the case in returning .some length of the column .to .stor- .age, the U-shaped lever 58, is thrown down .to the position indicated by the broken lines in Fig. 2. In the down movementthe side arms .of lever 58 come in .contact with the outer arms 59, 59 of the cam levers 59, 59, carrying them .along and raising the inner ends outof contact with Jtheedges of thestrips Raised in this position the .cams 59, 59 offer free passage to thestrips and to the links 2, 2. Furthermore this position of the cams is self-maintained as long as the U-Shaped lever58, remains down as shown bythe broken lines. This leaves the operator free to manipulate the levers 33, 33, to release brakes 2-1, .21, during the downward travel of the links toward storage, thus preventing them from piling up above the location of the brakes. As a matter of convenience in operation the outer ends of the levers 33, 33 may be connected by a bar 33a to .forma U-shaped lever similar to 58. It is obvious that should it be desirable to counteract any upward thrust of the column or the parts, an arrangement similar to the one above described, but operating in a reverse'direction, could be installed without departing from the spirit of my invention. 3 In the structure illustrated in Figs. 8, 9, 10, 11 and 12, I have provided a latch device to perform the sameduty as that performed by the cam levers, above described. This latchmechanism consists of a sliding bolt 69, mounted in and moving through a rectangular opening 6| in the upper portion of wall 35, Fig. 12. This bolt passes through the wall35, and project normally, beyond and to the right of a shoe-piece 62 carried by the wall 35, and'into the path followed by the hinge-pins 5a, 5a, in their upward travel. The bolt 69 is held in this forward position by the compression "spring 63, which lies in a rectangular opening 64 formed 'Withinthe bolt 69. The left end of this spring is held in place by a bracket 64, attached-to wall '35, and the right endis pressed against the right end of the opening in the latch bolt 69. Normally, the bolt 69, is maintained in proper'position by the shoul ders 65, 65, on its upper and lower edges which come into-contact with the outer surface of wall 35. The right end of thelatch bolt 69 is vertically inclined in such fashion that each hinge-pin 5a, in passing upward along the inclined face 66 of shoe 62, drives the bolt back to the left until it passes the'upper edge of the bolt,

whereupon, the bolt springs back beneath the hinge pin and lies in a position to check .any backward movement of the pin and associated parts. Withthe movement of the assembled col- .umn structure stopping there the column will be back manually, and retained in that position by lowering the lever 67, Fig. 11, in a manner to rest behind the upper shoulder on the latch bolt.

Obviously, the right end of the latch bolt 69 may be forked in such a way as :to prevent movement of the hinge pin in either direction or the taper may be reversed so as to check only an upward movement of theco'lumnj andsuch changes may be efiected without -departin g fromthe spirit of my invention.

Above the position of the shoe piece 62, and on the right hand side of the gap occupied by the column, is another shoe 68, Fig. 9. The horizontal distance between these two shoes is just suflicient to accommodate the width of the assembled column. The vertical distance between these shoes is approximately the vertical distance between hinge pins a, and 5b, when these are properly assembled in the column. These shoes, operate to prevent any sway of the column whenever the vertical movement of the parts brings them under the influence of the guides 4|, 4|, 42, 42, and latch bolt 60.

At this point, it is well to draw attention to the advantage which inheres in a mechanism of the kind under consideration in which the strips l, I, and la, la as employed, are normally of a transversely non-planar, or arcuate shape. Such strips have an inherent stifiness which ob viously adds considerably to the rigidity of the combined columnar structure; but this rod-like device also, performs an ofiice in the movement of the parts which would be impossible to a limp strip of spring material. For not only do such strips have an inherent tendency to straighten out but in the arrangements shown in the foregoing description and figures, these strips I, I, la, la, are relied upon to convey a compressive endwise thrust-from the reels l5, l5, l5a, l5a, to the column, whenever the latter is in process of upbuilding. By reason of both the stiffness and the ability to bend, these non-planar strips furnish power to unwind and convey the thus freed force through a most circuitous path to actuate the inert and stored links by drawing them out of their folded positions and carrying them into combination, automatically. In fact, the use of nonplanar strips of this description simplifies the entire operation and construction of the mechanism.

The composite structure shown in Figs. 13 to 16 inclusive difiers, chiefly from those shown in previous figures by the employment of a flexible strip lb, which unlike the strips l, l, and la, la of the preceding combinations, is one that remains transversely planar at all times throughout the operation, either in combination as a member of the composite structure, or when dissociated therefrom. But the diagonal bracing members 2b, 2b, are like those shown in the type of structure illustrated in Figs. 1 to 5, inclusive. For, in the present arrangement the diagonal bars surround the flexible strip members lb, lb. However, the openings 3b, 3b in the present structure are not elliptical but straight sided narrow slot-s snugly fitting over the planar strips lb, lb. Both the strip and the diagonal bar members bear .the same relation to one another as do those of the device shown in Figs. 1 to 5, inclusive.

The present structure employs a toggle system similar to that belonging to the structure shown in Figs. 6 to 12 inclusive; but in the present case a double system of toggles is employed, one along each of the opposite edges of the strips. The shape of the present toggle arms 20a, 20b, differs somewhat from those used in the former case, being designed so that when the joint isset just ofi the dead center the outer edges of the arms 20a, 20b present a straight line which parallels the edge of the strip lb adjacent thereto. Toggle arm 29a is also of U-sh'ape, and the transverse portion 69 of the U is slotted as indica'ted-at 70 in such fashion as to fit down over the edges of strips lb, lb, when the'arms' are at rest against the edges of the strips lb. The slot 10 aids in keeping the strips lb, lb in line during any compressive strain placed thereon.

As is shown in Figs. 13, 14 and 15, two-rollers H, H supported by the housing walls 24b,.24b, are so placed as to bear on the outer edges of toggle arms 20a, 20b, when the latter lie in line parallel to the edges of the strips, lb, lb as described above. When in moving'out of storage, the toggle arms lie out of line their passage under the rollers ll, ll,-forces them to assume the proper position, by pressing the arms down into a straight line parallel to the edges of the strips lb, lb.

Between rollers ll, ll, and the storage space 6b holding the folded toggle bars, rotatable disks 12, 12, are located. Lugs 13, 13, are projections on the hinge pins 2| b of the toggle joints. During their passage to and from the storage'position these lugs are forced to pass over the rims of 'the disks [2, l2 consequently, in being returned to the storage position these lugs l3, 13, are forced out beyond the dead center position causing the toggle arms to assume a bowed shape as the lugs pass "over the rimsof the disks. From that shape the toggle arms fold automatically, into compact shape'upon'further'movement of the'composite structure toward the storage position.

In the chamber 22b formed below the base plate llb, two-spring actuated reels l5b, l5b, are mounted to rotate on stationary arbors 23b, 23?), the ends of which are seated in the squared holes in the sidewalls l4, H of the chamber. Lying within each reel-drum isa coiled spring 15, one end of which is anchored in a slot-of the stationary arbor 23b, while the other end of the spring is riveted or otherwise secured to the interior wall of the drum.

Passing through an aperture in base plate I lb, the. strips lb, lb,- are led down the reel drums 15b and are attached to the exterior peripheral walls thereof. Witheach spring 15,-havingan initial tension even with" the strips fully Wound upon the drum, the strips lb, lb, remainunder tension at all times and are wound upincoils upon the reel-drums, automatically, whenever the composite column structure is pushed toward-the storage position. The tension'inthe present instance, while sufficient to wind up all of the slack in the strips as released from the composite structure, is not great enoughto overcome the friction and inertia of the othermoving parts and thus cause a retractile movement of the structure as awhole. It will be understood, however,'that in case a stronger tension isemployed, or absolute locking is desired, retarding'or locking devices similar in efiect to those employed in connection with the mechanisms shown'in Figs. 1, 2, 3 and 4, or Figs. 11 and 12, may be provided.

-In-pas sing to and fro the strips lb, lb, pass between anti-friction rollers 16, 16, below which point 2:2 their paths separate to join their in dividual reels. In 'view of the non-rigid character of strips lb, lb their travel outward must be broughtabout by a tensile reaction from the point of, or-beyond the position of assembly of the parts into the ultimatestructural formation, Ordinarilythis would be effected by pulling on the extended portion ofthe structure itself. Hence the entire movement of strips lb, lb, is dependent upon tensile force as contrastedto that'of .strips l,. I, and 1a,. :la of the previously described devices. Obviously in: 'each'of "the structures one of the strips I, Ia or lb, may be eliminated and the rigidifying structure made to embrace the remaining single strip solely to form a composite column, with the single strip of a thickness corresponding :to the combined thicknesses of the plurality of strips, if desired.

Figs, 17 to 21, inclusive, illustrate an improved type of adjustable platform 80 in which the height .of the platform is varied by means of changes effected in the length of the supporting column. The supply of component members entering into the column assembly is stored in the .casing which surrounds the base forming the pedestal .of the column. Thesemembers thus stored are .drawn from their stores automatically whenever the length of the column is increased.

The members composing the column consists of three flexiblespring strips Id, Id, Id, and three chain-like structures made up of transverse tie rods 99, 99, 99, connected by links 2d, 2e, etc. this form of my invention the term element referred to in certain of the appended claims may comprise the rod 99. The spring strips Id, .Id, Id, are normally of a transversely planar shape and when stored, remain in that condition, where 1 they are wound upon individual reels I5d, I5d, 15d, these reels lie within a hollow pedestal casing 9|. The chain-link members are foldable and when out of use lie stacked in folded condition in individual recesses 92 of the pedestal casing. From their respective stores these several members are drawn upward to the point of assembly to form the column structure, whenever. the platform 89 is raised.

The reels I5d, I5d, I5d, are rotatablymounted 2;

upon stationary arbors 23d, 23d, 23d, the latter being supported by the casing walls. Within the interior of each winding drum of the reels is a coiled spring 15d, the inner end of which is anchored in a slot of arbor 23d, while the other end of the spring is riveted or otherwise secured to the interior peripheral wall of the reel drum. The lower end of each strip Id, is fastened to the periphery of the drum of its respective reel.

The spring lid is arranged to provide an initial tension such that it exerts a pull on the strip Id at all times. Whenever the length of the composite column is shortened the reel takes up all the slack in the strip by winding it into a coil IBd over the drum In this instance, as in the case of the structure shown in Figs. 13 and 14, supra, the tension, While sufficient to wind up all the slack in the strips as released from the composite structure is not great enough to overcome the friction and inertia of the other moving parts causing a retractile movement of the structure.

The chain components, when stored, repose in folded form within individual recesses 92 formed by the pedestal casing 9|, where they are forced during the retrograde movement from the point of column assembly. At the upper portion of the chamber two retarding springs 93, 93 project into the passageway which act as stops to the stack of links forced upward by compression spring 94, acting on plunger 95, which supports the stack of links above. Whenever the movement to increase the length of the column draws upon the store of links, the upper link unfolds by forcing its end by the opposing spring '93,

In moving between storage and the point of assembly each chain is engaged by a sprocket wheel 96, and during any retrograde movement the links are forced back, serially, and fold :into

Inc

the stack as they emerge from the teeth of the sprocket wheel.

When in column assembly the severa1 component members of the structure must be arranged as shown in Figs. 19 and 21, with the edges 8d, 8d of the strips Id, Id, Id, resting securely in the recesses 91, 91, formed by hooked ends 99, 99 of the tie rods 99, 99, 99. As the width of the strips is greater than the distance between these hooked recesses the strip must be forced toassume a transversely non-planar shape. Furthermore, in order to assemble any strip within the recesses of any tie-rod it will be necessary to bend the strip into a degree of curvature beyond that assumed when lying within those recesses,

which 'must be done in order to pass the points of the hooks. After the passage has been made the strip automatically spreads out and seats itself tightly in the hooked recesses, where it lies under strong tension.

It must be remarked that as these three strips Id, Id, Id leave their'respective reels 5d, 15d,

I5di, they are transversely planar and as they approach one another, in rising, their transverse shape, taken together, forms the figure of an equilateral triangle, in cross section, which can-- not in that shape be included in the triangle formed by the combined tie-rods 99, 99, 99, and therefore, to enter into combination with them, the strips must be sprung sufficiently to pass the hooks 98 of the tie-rods. This is indicated in Fig. 19 and, to produce this effect, the three broad sprocket wheels 96, 96, 99, have been provided with the transversely curved or crowned periph eral faces and adjusted with relation to the center of the column as to force the strips into the curvature such as may pass the points of the hooks 98 on the tie-rods 99. The edges 8d of the strips Id remain tightly pressed together. The point of extreme pressure is opposite the .axes of the sprocket wheels which convey the tie-rods to the same point, so that the assembly is effected at that point in the progress. As the parts pass beyond this point the pressure recedes and the strips spread out and rest in the recesses of the hooked tie rods.

It is obvious that the reverse movement of the parts .will effect the separation of the members forming the column and that these mem bers will be deposited in their respective storage places.

The tie rods 99, 99 of each of the chains are connected together to form the chains by links 2d and 2e. The sprockets 99, 96 are circumferentially grooved at I99 and I 9! to receive these links and the sprockets are grooved transversely at I92 to receive the tie rods 99.

In each instance theouter free end of the link structure which embraces the strip members I, la, lb, Id, is connected to the strip members as clearly indicated iniFigs. 1, 6, 9a, 13 and 15a, by short links 2f having pivotal connection with the strip members, as indicated at 5f and with the link elements as at 56, so that the link members will be drawn out of storage at the same time as the free outer ends of the strip members move outwardly from the assembling devices, and vice versa.

As shown in Fig. '6, for example, the composite structure, when desired, may be completely removed from the assembling and disassembling device for use independent thereof, as a beam, for example. Then by merely reinserting the last assembled end of composite structure into the disassembling device and applying longitudinal thrust thereto the composite structure will be collapsed and dismembered in the storage spaces reserved for the various component parts of the structure.

In each instance, whether the composite structure is only partially extended from the assembling and disassembling device, or completely disconnected therefrom as noted above, the articulated series of strip embracing elements, being inherently rigid when extended into contact with the strips in the composite structure, resist torsional as well as tensile and compressive stresses about the longitudinal axis of the composite structure by reason of the clamping engagement of the embracing elements with the longitudinal edges of the strips, which in structures em bodying a plurality of strips prevents relative movement between the abutting longitudinal edges of the strips and thus aids the strips in resisting torsional, tensile, and compressive tendencies.

I claim:

A collapsible composite structure comprising a plurality of resilient strips collectively forming the main body of said structure, a series of pivotally connected extraneous elements disposed outside and diagonally crossing from edge to edge of said body and engaging aligned pairs of the longitudinal edges of said strips at relatively spaced points along the length of said body for rigidifying said structure and rigid means extending from one to the next of said relatively spaced points and there connected to said extraneous means to maintain said spacing of said points.

2. A collapsible composite structure comprising a plurality of resilient strips collectively forming the main body of said structure, a series of pivotally connected extraneous elements disposed outside and diagonally crossing from edge to edge of said body and engaging aligned pairs of the longitudinal edges of said strips at relatively spaced points along the length of said body for rigidifying said structure, means for automatical ly assembling and disassembling the components of said structure upon relative longitudinal movement of said structure from and toward said means, and means bearing against said extraneous elements to effect pivotal movement of said extraneous elements for attaining contact thereof with said strips at said spaced points during concurrent movement of said strips and said extraneous elements outwardly from said assem bling means.

3, A collapsible composite structure comprising a plurality of resilient strips collectively forming the main body of said structure, a series of pivotally connected extraneous elements disposed outside and diagonally crossing from edge to edge of said body and engaging aligned pairs of the longitudinal edges of said strips at relatively spaced points along the length of said body for rigidifying said structure, means for automatically assembling and disassembling the components of said structure upon relative longitudinal movement of said structure from and toward said means, means bearing against said extraneous elements to effect pivotal movement of said extraneous elements for attaining contact thereof with said strips at said spaced points during concurrent movement of said strips and said extraneous elements outwardly from said assembling means, and means for releasing said bearing means to allow for disassembling of said struc- 4. A collapsible composite structure comprising a plurality of resilient strips collectively forming the main body of said structure, a series of pivotally connected extraneous elements disposed outside and diagonally crossing from edge to edge of said body and engaging aligned pairs of the longitudinal edges of said strips at relatively spaced points along the length of said body for rigidifying said structure, toggle levers connected to the pivots of said extraneous means at said spaced points and pivotally connected together intermediate said points, means for assembling and disassembling the components of said structure upon longitudinal movement of said structure relative to said assembling and dissambling means, including means for straightening said toggle levers intermediate said points upon outward movement of said structure to prevent longitudinal collapse of said structure.

5. A collapsible composite structure comprising a plurality of resilient strips collectively forming the main body of said structure, a series of pivotally connected extraneous elements disposed outside and diagonally crossing from edge to edge of said body and engaging aligned pairs of the longitudinal edges of said strips at relatively spaced points along the lenth of said body for rigidii'ying said structure, toggle levers connected to the pivots of said extraneous means at said spaced points and pivotally connected together intermediate said points, means for assembling and disassembling the components of said structure upon longitudinal movement of said structure relative to said assembling and disassembling means, including means for straightening said toggle levers intermediate said points upon outward movement of said structure to prevent longitudinal collapse of said structure, and means for breaking said toggles at said intermediate points to allow disassembling of said structure.

6. A collapsible composite structure comprising a plurality of resilient strips collectively forming the main body of said structure, a series of pivotally connected extraneous elements disposed outside and diagonally crossing from edge to edge of said body and engaging aligned pairs of the longitudinal edgesof said strips at relatively spaced points along the length of said body for rigidi fying said structure, toggle levers connected to the pivots of said extraneous means at said spaced points and pivotally connected together intermediate said points, means for assembling and disassembling the components of said structure upon longitudinal movement of said structure relative to said assembling and disassembling means, including means for straightening said toggle levers intermediate said points upon outward movement of said structure to prevent longitudinal collapse of said structure, and means engageable with said structure to prevent inward movement thereof with respect to said assembling and disassembling means.

7. A compound structure capable of lengthwise extension and contraction and comprising a main body strip of flexible material, and a rigidifying structure coextensive with said strip and comprising a series of transverse members engageable with the opposite edges of said body strip at spaced intervals longitudinally of said strip, and a chain of successively connected elements pivotally attached to said transverse members and arranged with alternate connections of said chain adapted to lie in a common line longitudinally of said strip, with the intermediate conaccascs nections movable laterally to one side of said line to lock said elements in rigidifying positions-and prevent lengthwise contraction of said structure and to the opposite side of said line to unlockv said elements and permit said lengthwise contraction of said structure.

8. A compound structurecapable of lengthwise extension and contraction and comprising a main body strip of flexible material and a rigidifying I structure coextensive with saidstrip and compris ing a series of transverse members engage able with the opposite edges of said bodystrip at spaced intervals longitudinally of said strip,

and a chain of successively pivotally connected elements pivotally attached to said transverse members and arranged with alternate connections of said chain adapted to lie in a common line longitudinally of said strip, with .the intermediate connections movable laterally to one side of said line into contact with said strip to lock said elements in rigidifyingpositions' and prevent lengthwise contraction of said structure and to the opposite side of said line to unlock said elements and permit said lengthwise contraction of said structure. v

9. In a compound supporting structure capable of variable lengthwise extension, component membersystems of differing physical character'- istics, said member-systems being jointly associated in a unit body to create said compound supporting structure in proportions varying with the lengthwise extension thereof, with such portions of said member-systems as may not be in association at any time being separable one from another, and different means for storing the dissociated portions according to their physical characteristics, one of said component members consisting of a flexible strip of relatively thin resilient material, and another of said members being composed of a chain of distinct ri d elements connected for free, pivotal, relative movement embracing said flexible strip for aiding resistance to torsional, tensile and compressive stresses with each element engaging the longitudinal edges of said strip independently of the other elements to maintain the structure rigid when said structure is in a partially collapsedor extended condition.

10. In a compound supporting structure capable of lengthwise extension, a plurality of component member-systems jointly associated to form a unit body, one of said member-systems consisting of at least one coilable strip of relatively'thin resilient material, and another of said'member-systems being composed of a foldable chain of rigid distinct coextensive and elements connected for free, pivotal, relative movement adapted to embrace the first said mem-- ber system along its length in the assembled composite structure and inherently opposing distortion of said structure relative to the longitudinal axis thereof, each element engaging the longitudinal edges of said strip'independently of the other elements to maintain the structure rigid when said structure is in partially collapsed or extended condition.

11. In a compound supporting structure capable of variable lengthwise extension, aplurality of components including a flexible strip member of resilient materialcapable of alternately assuming a rectilinear or a curvilinear longitudinal formation, said strip member being substantially coextensive with said compound supporting structure and when in -=combination therewith assuming said rectilinear longitudinal and a normal transverse formation, a stress .resisting component comprising a series of distinct rigid elements connected for free, pivotal, relative movement embracing said strip member when insaid rectilinear formation, said strip being separablefrom said stress resisting component whennot' in saidcombination and assuming said curvilinear formation while said seress resisting component assumes a folded formation,

each element engaging the longitudinal edges of said strip independently of the other elements to maintain thestructure rigid when said structure is in partially collapsed or extended condition.

12. A compound. supportingstructure capable of variable lengthwise extension and comprising a plurality of component members including at least one flexible strip of resilient material forming a web-membersubstantially coextensive with said structure in a longitudinal direction thereof, and a series of, distinct rigidv elements connected for free, pivotal, relative movement forming a system of lateral tie and brace' members over a common length of said structure, said components comprising in union a reinforced structural supporting body capable of resistance to torsional, tensile. and compressive .stresses, said web-member and said system of lateral tie and brace members combining in effective amounts varying in proportion to the length of the extended portion of said body and when not so combinedbeing separable one from the other, the relation between the external cross-sectional configuration and dimensions of said strip member and the internal configuration and dimensions of each tie and brace members causing said tie and'brace members to assume automatically longitudinal and transversestrip embracing positions over the length of said body during cone current movements of said components toward the point of assembly of said structure, each element engaging the longitudinal edges of said strip independently of the other elements to maintain the structure rigid when said structure is in partially collapsed or extended condi-.

tion. 13. A compound supporting structure capable of variable lengthwise extension comprising a plurality of component members including at least one flexible strip'of relatively .thin resilient material,astress resisting member embracing said strip and consisting .of a series of substantially distinct rigid elements connected for free, pivotal, relative movement, the embrace of said strip by said rigid elements being thesole means of -en gagement between said component members along a substantialportion of thelength of said compound supporting structure, and said embrace being of a readilyreleasable character in order that varying lengths of both components may be released therefrom, each element engaging the longitudinal edges of said'strip indee pendently of the other elements to maintain-the structure rigid when said. structure is in partially collapsed or extended condition.

14. Ina compound supporting structure capable of variable lengthwise extensions, a flexible main body component, a stress resisting component separable from said main body and com-'- prising a continuous extensible and collapsible system of distinct rigid, elements connected for free, pivotal, relative movement adapted when extended to embrace said main bodywith each of the elements engaging the longitudinal edges of said main body independently of the other elements to "maintain the structure rigid and for 

